Class 19:Anonymity in

Bitcoin

Cryptocurrency Cabalcs4501 Fall 2015

David Evans and Samee ZahurUniversity of Virginia

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What is anonymity?anonymous

pseudonymous

unlinkable

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Unlinkability of Bitcoin Transactions

If Alice conducts two bitcoin transactions using different bitcoin addresses (“pseudonyms”), how hard is it for those transactions to be linked?

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Linking Transactionshttps://blockchain.info/tx/0197dabc3c31c8221b5d7883a9d03240bcf7a3042e1bf6dcc26c8d3aa60c58ab

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Confounding Transaction Tracers

"CoinJoinExample" by MARIODOESBREAKFAST - Image drawn for CoinJoin article. Licensed under CC BY-SA 3.0 via Wikipedia - https://en.wikipedia.org/wiki/File:CoinJoinExample.svg#/media/File:CoinJoinExample.svg

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Mixers

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Mixer Design

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Silk Road

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Illegal drugs are illegal and can rot your brain and destroy your (and others) lives!

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This is current!https://www.linkedin.com/in/rossulbricht

My goal during this period of my life was simply to expand the frontier of human knowledge.

Now, my goals have shifted. I want to use economic theory as a means to abolish the use of coercion and agression amongst mankind. … To that end, I am creating an economic simulation to give people a first-hand experience of what it would be like to live in a world without the systemic use of force.

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Silk Road Transactions

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Threats to Validity

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Communication Privacy

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USENIX Security 2004

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Onion Routing

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ChargeProblem Set 3 due SundayUpcoming office hours:

Today: 5-6:30pm (Ori, Rice 442) Wednesday: 3:30-4:30pm (Samee, Rice

442)Thursday: 2:30-3:30pm (Dave, Rice 507)